JPH0473191A - Material and method for heat-sensitive transfer recording - Google Patents

Abstract

PURPOSE:To obtain a favorable chelating reactivity and prevent coloring matter from being set off by providing a layer containing at least the coloring matter represented by a specific formula on a support. CONSTITUTION:An image receiving material is laid over the layer containing the coloring matter represented by the formula I formed on the support of a heat-sensitive transfer recording material and heated according to image information and an image is formed on the image receiving material by the chelate coloring matter formed by a reaction between the coloring matter and metal ions. In the formula I, X<1> is an atomic group forming an aromatic ring together with two carbon atoms, X<2> is an atomic group forming 5 or 6 membered nitrogen containing heterocyclic ring together with two nitrogen atoms and one carbon atom, G is a group capable of being chelated and R represents an alkyl group, alkoxy group, aryloxy group, amino group, alkylamino group, arylamino group or acylamino group.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal transfer recording material and a thermal transfer recording, and more particularly, the present invention relates to a thermal transfer recording material and a thermal transfer recording. 2. A heat-sensitive transfer recording material containing a heat-diffusible magenta dye; and 2. A heat-sensitive transfer recording material that can efficiently produce high-density color images with good fixing properties and image stability using this heat-sensitive transfer recording material. Regarding the method.

[Prior Art and Problems to be Solved by the Invention] Conventionally, color recording techniques such as ink sheets, electrophotography, and thermal transfer have been considered as methods for obtaining color hard copies.

Among these, the thermal transfer method in particular is easy to operate and maintain, and the equipment can be made smaller and lower in cost.
Furthermore, it has advantages such as low running costs.

This thermal transfer method involves heating a transfer sheet (thermal transfer material), which has a meltable ink layer on a support, with a thermal head to melt and transfer the ink onto the transfer sheet (image receiving material). , a transfer sheet having an ink layer containing a heat-diffusible dye (sublimable dye) on a support is heat-sensitive.
There are two types of thermal diffusion transfer methods (sublimation transfer methods) in which the heat-diffusible dye is transferred to the transfer sheet by heating with a dye. It is advantageous for full-color recording because it is possible to control the gradation of one image by changing the amount of dye transferred according to the change.

However, in thermal transfer recording using the thermal diffusion transfer method,
Dyes used in thermal transfer materials are important, and conventional dyes have had the disadvantage of poor image stability, ie, poor light fastness and fixing properties.

In order to improve this point, JP-A-59-7889:1, JP-A-59-109:194, and JP-A-60-2:198 disclose using a heat-diffusible dye that can be chelated. An imaging method is disclosed that forms an image with chelated dyes on an image-receiving material.

These image forming methods are excellent methods for improving light fastness and fixing properties. The magenta dye in the heat-sensitive layer migrates (set-off) to the back layer (usually the back coat layer) of the heat-sensitive transfer recording material, and when heat is applied with a thermal head,
There was a problem with contaminating the thermal head.

On the other hand, if a magenta dye is used that is less likely to migrate to the back layer, the sensitivity of the thermal transfer recording material will be lowered, leading to problems such as a decrease in image density and insufficient progress of chelation of the dye.

In order to obtain sufficient image density with this type of magenta dye, it is necessary to extend the heat application time to the thermal head or to maintain the temperature of the thermal head at a high temperature, which results in a lifespan of the thermal head. This has the disadvantage of shortening the image recording time and prolonging the image recording time.

The present invention has been made to improve the above situation.

That is, an object of the present invention is to provide a thermal transfer recording material containing a heat-diffusible magenta dye that has good chelation reactivity and prevents dye set-off, and to provide a thermal transfer recording material that has good fixing properties using this thermal transfer recording material. An object of the present invention is to provide a thermal transfer recording method that can efficiently obtain high-density color images having high image stability and image stability.

[Means for solving the above problem] The present invention according to claim 1 for achieving the above object,
This is a heat-sensitive transfer recording material characterized by having on a support a layer containing at least a dye represented by the following general formula [I].

The present invention according to claim 2 further provides an image-receiving material which is superimposed on the layer of a heat-sensitive transfer material having a layer containing a dye represented by the following general formula [1] on a support, and the image-receiving material is formed into an image of the heat-sensitive transfer material. This is a thermal transfer recording method characterized in that an image is formed on an image-receiving material by heating according to information and using a chelate dye formed by a reaction between the dye and metal ions.

However, in the formula, X' is an atomic group that forms an aromatic ring with two carbon atoms, and X2 forms a 5- or 6-membered nitrogen-containing heterocycle with two nitrogen atoms and one carbon atom. , and G is a chelatable group,
R represents an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylamino group, an arylamino group, or an acylamino group, each of which may have a substituent.

Furthermore, general formula [I] will be explained in detail.

xI represents an aromatic ring obtained by bonding two carbon atoms (preferably a 5- to 6-membered aromatic ring, particularly preferably a benzene ring), and this aromatic ring is fused with another ring (e.g. (naphthalene ring), and this aromatic ring may have a substituent. Examples of the substituent include an alkyl group (eg, methyl group, ethyl group, trifluoromethyl group).

Aryl groups (e.g., phenyl groups, etc.), alkoxy groups (e.g., methoxy groups, ethoxy groups, etc.), amino groups (e.g., methylamino groups, ethylamino groups, etc.), acylamino groups (
Examples include acetyl group, etc.), sulfonyl group (eg, methanesulfonyl group, etc.), alkoxycarbonyl group (eg, methoxycarbonyl group), cyano group, nitro group, and halogen atom (eg, chlorine atom, fluorine atom, etc.).

X2 is an atomic group that forms a 5- or 6-membered nitrogen-containing heterocyclic ring with two nitrogen atoms and one carbon atom, and this nitrogen-containing heterocyclic ring may form a fused ring with another ring. ,
Furthermore, this nitrogen-containing heterocycle may have a substituent.

This substituent may be combined with the substituent for xl.

G has a chelatable group, hydroxyl group, amino group, CO
OR2,5o2NHR2,OR'', or SR'' (where R2 represents a hydrogen atom, an alkyl group (preferably an alkyl group having 1 to 6 carbon atoms), or an aryl group (preferably a phenyl group), and R3 is An alkyl group (preferably an alkyl group having 1 to 6 carbon atoms), or an aryl group (
(preferably a phenyl group).

R represents an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylamino group, an arylamino group, an alkoxyalkyl group, or an acylamino group, each of which may have a substituent, and these groups have a carbon number of 8 or 8. It is preferable that it is the following.

Moreover, the substituent may be the same as the substituent for XI above.

Among the dyes represented by the general formula [I], preferred dyes include those represented by the following general formulas [Ia] and [Ibl].

However, in the general formulas [Ia] and [Ibl], G and R are the same as defined in the general formula [I].

R4 represents an aryl group (preferably a phenyl group) which may have a substituent or an alkyl group which may have a substituent, and R5 represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group.

The dye represented by the general formula [I], ie, the dye according to the present invention, is a magenta dye with excellent thermal diffusivity, and also exhibits good chelation reactivity with metal ions.

Typical examples of the dye according to the present invention are shown in FIG.

The dye according to the present invention is disclosed in, for example, JP-A-53-3551:
It can be produced according to the synthesis method disclosed in Publication No. 1.

The heat-sensitive transfer recording material of the present invention comprises a layer containing the dye according to the present invention (hereinafter sometimes referred to as a heat-sensitive layer) on a support.

The content of this dye in the heat-sensitive layer is as follows:
0.1g to 20g per serving is preferable.

The heat-sensitive layer is prepared by preparing a paint by dissolving one or more of the pigments together with a binder in a solvent or dispersing them in the form of fine particles in a solvent, and coating the paint on a support and drying it appropriately. By doing this, you can form it.

The thickness of the heat-sensitive layer is preferably 0.1 to 5 pm in dry film thickness.

Examples of the binder include water-soluble polymers such as cellulose, polyacrylic acid, polyvinyl alcohol, polyvinyl and lolidone, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyether sulfone, polyvinyl butyral, polyvinyl acetal, and nitro. Cellulose, ethylcellulose, etc. may be mentioned.

These binders can be used not only by dissolving one or more of them in an organic solvent, but also in the form of latex dispersion.

The amount of binder used is 0.000.
1 to 50 g is preferred.

The solvents include water, alcohols (e.g. ethanol, propatool), cellosolves (e.g. ethyl acetate), aromatics (e.g. toluene, xylene, chlorobenzene), ketones (e.g. acetone, methyl ethyl ketone), ethers (e.g. Examples include tetrahydrofuran, dioxane), chlorinated solvents (eg, chloroform, trichlorethylene), and the like.

The support may be one that has good dimensional stability and can withstand the heat of the heat-sensitive head during recording, but thin paper such as condenser paper or glassine paper, or heat-resistant materials such as polyethylene terephthalate, polyamide, or polycarbonate may be used as the support. A plastic film is preferably used.

The thickness of the support is preferably 2 to 30 pm, and the support may have a subbing layer for the purpose of improving adhesion with the binder and preventing transfer and dyeing of the dye to the support. good.

Further, a slipping layer may be provided on the back side of the support (the side opposite to the heat-sensitive layer) for the purpose of preventing the head from adhering to the support.

The heat-sensitive transfer material of the present invention is provided on the heat-sensitive layer by JP-A-59-10
It may have a heat-fusible layer containing a heat-fusible compound as described in Japanese Patent No. 6997.

As this heat-melting compound, colorless or white compounds having a melting point of 65 to 130°C are preferably used, such as waxes such as carnauba wax, beeswax, and campli wax, higher fatty acids such as stearic acid and behenic acid, Examples include alcohols such as xylitol, amides such as acetamide and benzamide, and ureas such as phenylurea and diethylurea.

Note that these heat-melting layers may contain a polymer such as polyvinylpyrrolidone, polyvinyl butyral, or saturated polyester, in order to improve the retention of the dye.

The heat-sensitive transfer material of the present invention can be used to obtain a magenta dye image from the dye, or when applied to full-color image recording, a cyan heat-sensitive layer containing a cyan dye, a magenta dye image containing a magenta dye according to the present invention, and a cyan heat-sensitive layer containing a cyan dye; It is preferable that a total of three layers, a heat-sensitive layer and a yellow heat-sensitive layer containing a heat-diffusible yellow dye, are successively and repeatedly coated on the same surface of the support.

If necessary, a yellow heat-sensitive layer, a magenta heat-sensitive layer containing the dye according to the present invention, a cyan heat-sensitive layer and a heat-sensitive layer containing a black image forming substance, a total of four layers, may be sequentially repeated on the same surface of the support. It may be painted.

In the heat-sensitive transfer recording method of the present invention, the heat-sensitive layer of the heat-sensitive transfer recording material and the image-receiving material are superimposed, heat corresponding to image information is applied to the heat-sensitive transfer recording material, and metal ions and dyes in the heat-sensitive layer react with each other. An image is formed on the image-receiving material by the chelate dye formed by the dye.

The metal ions may be present in the image-receiving material or in a heat-fusible layer provided on the surface of the heat-sensitive layer.

To explain the thermal transfer recording method of the present invention with reference to the drawings, in FIG.
The dye in the heat-sensitive layer 5 of the heat-sensitive transfer material 6 composed of the heat-sensitive layer 5 is diffused and transferred to the image-receiving material 3 by heat from the heat-generating resistor 8 of the thermal head 7, and is combined with the metal ions in the image-receiving layer 2. Reacts to form chelate dye.

Further, in FIG. 3, when the metal ions are present in the heat-fusible layer 9 provided on the surface of the heat-sensitive layer 5, the support 4
The dye in the heat-sensitive layer 5 of the heat-sensitive transfer recording material 1O, which is composed of a heat-sensitive layer 5 and a heat-fusible layer 9, is diffused and transferred to the heat-fusible layer 9 by heat from the heating resistor 8 of the thermal head 7, for example. , where it reacts with the metal ions to form a chelate dye, and the heat-melting substance 9a containing this chelate dye.
It is transferred to the image-receiving material 3 by cohesive failure or interfacial peeling.

Examples of the metal ions include divalent and polyvalent metals belonging to Groups 1 to 2 of the periodic table, including A, Co, Cr, Cu, Fe, Mg, Mn, and Mo.
, Ni, Sn, Ti and Zn are preferred, especially N
i, Cu, C', Co and Zn are preferred.

Compounds that supply these metal ions (hereinafter sometimes referred to as metal sources) include inorganic or organic salts of the metals and complexes of the metals, of which salts and complexes of organic acids are preferred.

Specific examples include Ni'', Cut+, C, 21'', G
o ” and lower fatty acid salts of Zn 20 and acetic acid etc.
Examples include salts of higher fatty acids such as stearic acid, and salts of aromatic carboxylic acids such as benzoic acid and salicylic acid.

Further, complexes represented by -Funzo below can also be preferably used.

[M(Ql) (02), (Q:l)n] ”(y
−).

However, in the above formula, M is a metal ion, preferably Ni'',
Cu2+'', Cr2*, co2'', Zn2''''
represents.

Ql, Q2. Q:l each represents a coordination compound capable of forming a coordination bond with the metal ion represented by M, and may be the same or different.

These coordination compounds include, for example, chelate chemistry (
5) (Nankodo).

Y represents an organic anion, and specific examples thereof include tetraphenylboron anion and alkylbenzenesulfonate anion.

The sentence represents an integer of 1, 2 or 3, m represents 1, 2 or 0, and n represents 1 or 0. Q2. It is determined by the number of ligands of Q.

p represents 1 or 2, preferably 2;

If p is 2, then Q, ,Q2. The coordination group of the coordination compound represented by Q is never anionized.

The amount of metal source added is usually 0.5 to 20 g/m2, preferably 1 to 20 g/m2, relative to the image receiving material or thermally fused layer.
g/m2 is more preferable.

The image-receiving material used in the present invention generally has paper, a plastic film, or a paper-plastic film composite as a support, and an image-receiving layer formed on the support by polyester resin, polyvinyl chloride resin, vinyl chloride, or other materials. - (for example, vinyl acetate, etc.), one or more polymer layers such as polyvinyl butyral, polyvinylpyrrolidone, polycarbonate, etc. are formed.

Further, the support itself may be used as an image-receiving material.

According to the thermal transfer recording material and thermal transfer recording method of the present invention, images with excellent single image stability and fixability can be obtained.

Furthermore, even if the thermal transfer recording material is stored in a cassette for a long period of time, set-off is unlikely to occur.

Therefore, the contamination of the thermal head caused by dyes can be significantly reduced.

Furthermore, although dye set-off is less likely to occur as described above, the thermal transfer recording material of the present invention can suppress a decrease in sensitivity and increase image density.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited thereto.

(Example 1) Preparation of Paint The following raw materials were mixed to obtain a uniform solution paint containing the heat-diffusible dye according to the present invention.

Heat-diffusible dye M-1...10g Nitrocellulose resin...20g Methyl ethyl ketone...400rnJ1 Preparation of heat-sensitive transfer recording material Apply the above paint to a thickness of 4 .5 pm polyethylene terephthalate film using a wire bar to a coating weight after drying of 1.0 g/m', and drying to form a heat sensitive layer on the polyethylene terephthalate film to obtain a heat-sensitive transfer recording material. Created.

Note that a nitrocellulose layer containing a silicone-modified urethane resin (SP-2105, manufactured by Dainichiseika Chemical Co., Ltd.) is provided on the back surface of the polyethylene terephthalate film as a sticking prevention layer.

Preparation of image-receiving material - As shown in FIG.
On one side of the polyethylene layer 12a [containing a white pigment (TiO□), a bluing agent, and the following metal source (applied amount: 5 g/m2)] on which 2a and 12b are laminated, 0.15 g/m2 of the image receiving layer 13 is applied. A vinyl chloride resin containing silicone oil of 10 g/m 2 was coated to obtain an image-receiving material.

Thermal transfer recording method - The thermal transfer recording material and the image-receiving material are stacked so that the surface of the heat-sensitive layer of the thermal transfer recording material and the image-receiving surface of the image-receiving material face each other, and a thermal head is applied from the back side of the thermal transfer recording material,
Image recording was performed under the following recording conditions.

As a result, a magenta image with excellent gradation was obtained.

The maximum reflection density (D-,...), dye chelation reactivity, fixing properties, dye set-off, and image stability (lightfastness) of this image were evaluated in the following manner, and the results are shown in Table 1. show.

Linear density of main scanning and sub-scanning: 8 dots/■■ recording electric crab 0.6 W/dot Heating time of thermal head: The heating time was adjusted stepwise between 20 m5 ec and 0.2 m5 ec.

Maximum reflection density: Measured using an optical densitometer [Model PCA-65 manufactured by Konica Corporation.

Evaluation of chelation reactivity.

○ Forms a sufficient chelate dye image.

△: Insufficient formation of chelate dye.

×D Only some pigments form chelate pigments.

Evaluation of fixability: The surface of the image-receiving layer of the obtained image was overlapped with the coated surface of a transfer sheet made by coating a 5 pm thick nitrocellulose layer on a 180 gm thick polyethylene terephthalate film, and then heated at 140°C for 1 minute. The degree of transfer of the dye from the image-receiving layer to the surface of the nitrocellulose layer was visually evaluated by heating, and it was determined that the less retransfer, the better the fixing property.

O: Re-transfer, hardly recognized.

△... Re-transfer or not recognized.

×... Re-transfer is noticeable.

Set-off: The surface of the heat-sensitive layer of a heat-sensitive transfer recording material and the surface of the back coat layer are stacked and molded for 30 minutes, and then the temperature is changed, thereby measuring the degree of transfer of the resulting dye to the surface of the back coat layer. was evaluated visually.

O... There is almost no migration at 50°C.

△...A slight shift is observed at 50°C.

×...Transition is observed at 40°C.

Image stability: After the sample was irradiated with light for 96 hours using a xenon phase meter, the residual rate of image density was shown.

Metal source: [N1(C2H5NHCH2CH2NH2)]”[(C
68S)4B]2-The characteristics of these images were measured in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Examples 1 and 2) Two types of thermal transfer recording materials were prepared in the same manner as in Example 1, except that dye M-1 in Example 1 was replaced with comparative dyes A and H below. Image recording was performed under the recording conditions.

The characteristics of these images were measured in the same manner as in Example 1, and the results are shown in Table 1.

Comparative dye A: (Examples 2 to 8) Dye M-1 in Example 1 was replaced with M-3, M-6, M-8
, M-9, and M-10 were used, but five types of thermal transfer recording materials were prepared in the same manner as in Example 1, and images were recorded under the same recording conditions.

As a result, magenta images with excellent gradation were obtained in all cases.

Comparative dye B: OCR.

As can be seen from Table 1, in Comparative Example 1, there was significant dye set-off and the light resistance was not good.

In addition, in Comparative Example 2, maximum reflection density, chelation reactivity,
Poor fixability, set-off, and light resistance.

(Hereinafter, blank space) Table 1 (Example 9) As shown in FIG. A yellow heat-sensitive layer 15 containing a yellow dye, a magenta heat-sensitive layer 15 containing a magenta dye M-1 according to the present invention, and a cyan heat-sensitive layer 17 containing a cyan dye having the following structure are sequentially coated to prepare a heat-sensitive transfer recording material. did.

Cyan dye: H OCH(CH3)2 Ikoro dye: The amount of coating was 0.5 g/rn'.

Hardening agent: Na Further, on the intermediate layer, as a heat-fusible layer, the metal source (applied amount 1.0 g/rn') and the following ultraviolet inhibitor (
0.1g/rrf), the following antioxidant (0.1g/rn') and ethylene-vinyl acetate copolymer (vinyl acetate content 20% by weight, 0.2g/m)
A heat-sensitive transfer recording material was obtained by applying carnauba wax (coating amount: 2.0 g/ba) containing (2.0 g/ba) by hot-melt coating.

Using this heat-sensitive transfer recording material and image-receiving material, a full-color image was recorded using a video printer in the same manner as in Example 9.

Note that plain white paper was used as the image-receiving material.

The obtained image had good gradation and image stability.

UV inhibitor; C4H9(D Antioxidant.

[Effects of the Invention] According to the present invention, there is provided a thermal transfer recording material containing a magenta dye that has good chelation reactivity and prevents dye set-off, and a thermal transfer recording material that has good fixing properties using this thermal transfer recording material. It is possible to provide a thermal transfer recording method for efficiently obtaining a high-density color image having high image stability and image stability.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the structural formula of a representative example of a magenta dye according to the present invention. FIGS. 2 and 3 are explanatory diagrams of the thermal transfer recording method of the present invention. FIG. 4 is a sectional view showing an example of an image receiving material. FIG. 5 is a sectional view showing an embodiment of the thermal transfer recording material of the present invention. DESCRIPTION OF SYMBOLS 1...Support, 2...Image receiving layer, 3...Image receiving material,
4... Support, 5... Heat sensitive layer, 6... Heat sensitive transfer recording material, 7... Thermal head, 8... Heat generating resistor, 9... Heat melting layer, 10...・Thermal transfer recording material,
11...paper, 12a, 12b...polyethylene layer,
13... Image receiving layer, 14... Polyethylene terephthalate film, 15... Yellow thermosensitive layer, 16...
Magenta heat-sensitive layer, 17... cyan heat-sensitive layer.

Claims (2)

[Claims] (1) A thermal transfer recording material characterized by having on a support a layer containing at least a dye represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [However, in the formula, X^1 is an atomic group that forms an aromatic ring with two carbon atoms, and X^2 is a group of atoms that forms an aromatic ring with two nitrogen atoms. An atom group that forms a 5- or 6-membered nitrogen-containing heterocycle with 5 carbon atoms, G is a chelatable group, and R is an alkyl group, an alkoxy group, each of which may have a substituent, It represents an aryloxy group, an amino group, an alkylamino group, an arylamino group, an alkoxyalkyl or an acylamino group. ] (2) An image-receiving material is superimposed on the layer of a heat-sensitive transfer material having a layer containing a dye represented by the general formula [I] according to claim 1 on a support, and the heat-sensitive transfer material is transferred according to image information. A thermal transfer recording method, characterized in that an image is formed on an image-receiving material by heating and using a chelate dye formed by a reaction between the dye and metal ions.